Add test app checks-root

tests/apps/checks-root/index.js

@@ -0,0 +1,11 @@
+var express = require('express');
+var app = express();
+
+app.get('/', function(req, res) {
+  res.sendStatus(404);
+});
+
+var port = process.env.PORT || 5000;
+app.listen(port, function() {
+  console.log('Listening on port ' + port);
+});